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Adams, Terry R.

Publications and source records attributed to Adams, Terry R..

MCNP ® Code Version 6.3.1 Theory & User Manual

This document acts as a repository of knowledge for the Monte Carlo N-Particle (MCNP) transport computer code. It is maintained alongside the source code and attempts to introduce new users and re-familiarize experienced users with the theory and practices of using the MCNP code for the wide range of particle transport analyses that it is appropriate for. The latest version of the MCNP code, version 6.3.1, provides the Monte Carlo particle transport community with the latest feature developments and bug fixes in the MCNP code. The MCNP code version 6.0 and later is also known as the MCNP6 code.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

MCATK: Mesh and Material Indexing with Domain Decomposition [Slides]

Slides documenting some of the basics in how MCATK handles the mesh, mesh indexing, materials (IDs and Densities), material indexing, and domain decomposition indexing. These basics hold when using the hybrid parallelism; a full domain decomposition is one replica; a full domain replicated is when number of replicas equals the number of ranks; for the other cases of replicas then the decomposition is what is described here within each replica.

36 MATERIALS SCIENCE↗

MCNP ® Code Version 6.3.0 Theory & User Manual

This document acts as a repository of knowledge for the Monte Carlo N-Particle (MCNP) transport computer code. It is maintained alongside the source code and attempts to introduce new users and re-familiarize experienced users with the theory and practices of using the MCNP code for the wide range of particle transport analyses that it is appropriate for. The latest version of the MCNP code, version 6.3.0, provides the Monte Carlo particle transport community with the latest feature developments and bug fixes in the MCNP code. The MCNP code version 6.0 and later is also known as the MCNP6 code.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗

Coordinate Transformations

This whitepaper provides details for the background, conventions, definitions, transformation equations, examples, and implementation used in the Solid Body Geometry (SBG) transformations in Monte Carlo Application ToolKit (MCATK).

97 MATHEMATICS AND COMPUTING↗

Upcoming MCNP6.3 ® Release: New Features and Improvements [Slides]

The latest version of the MCNP6.3 code will be done and released this year. Many new features, substantial improvements, and bugfixes have made their way into the code. Improved documentation, testing, and peripheral tools will also be delivered.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Recent MCNP6 ® Code Developments and Improvements for Nuclear Engineering Applications [Slides]

The Los Alamos MCNP Monte Carlo radiation transport code has been the international gold standard for particle transport applications for over three decades. Many developments to the code have taken place with several significant new feature additions, major improvements, and enhancements to existing features. With significant institutional and programmatic investment in the code since the time of the last public release in 2018, important code development and infrastructure modernization has taken place and remains a high priority for all ongoing efforts across the code development team.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Implementation of Doppler Broadening of the Neutron Elastic Scattering Cross Section in MCATK (U)

The ability to Doppler broaden the neutron elastic scattering cross section as a function of cell material temperature has been added to the Monte Carlo Application Toolkit (MCATK). Two different computational methods have been tested for speed and correctness. The implementation has been tested against Doppler broadened nuclear data generated using the NJOY nuclear data processing code. The implementation in MCATK compares well with the tabulated data from NJOY, typically within 0.25%. Note, version 2.0 has clarifying changes only compared to the October 2, 2012 version (LA-UR-12-25645).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Continuous Integration! You Keep Using Those Words. I Do Not Think They Mean What You Think They Mean.

Continuous Integration (CI) is a best practice in the software community. Often though, there are several ideas as to what it means to practice continuous integration. With this uncertainty of the definition often comes a loss of benefit. It is good to stop and reflect on how and why CI has been, and still is, practiced in software community. So, presented here is a historical prospective of CI along with associated practices, anti-patterns, and benefits. A subsequent presentation will discuss the workflows and the controversy that arises as CI has changed with time, especially in regards to feature-branch development.

97 MATHEMATICS AND COMPUTING↗

Continuous Integration! You Keep Saying Those Words. I Do Not Think They Mean What You Think They Mean [Slides]

Continuous Integration (CI) is a best practice in the software community. Often though, there are several ideas about the meaning of continuous integration. With this uncertainty of definition often comes a loss of benefit to the practice. It is good to stop and reflect on how and why CI has been (and still is) practiced in software community. So, presented here is a historical perspective of CI along with associated practices, anti-patterns, and benefits. A subsequent presentation will discuss the workflows and controversy that had arised as CI has “changed” with time, especially in regards to feature-branch development.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Continuous Energy Photon Transport Implementation in MCATK

The Monte Carlo Application ToolKit (MCATK) code development team has implemented Monte Carlo photon transport into the MCATK software suite. The current particle transport capabilities in MCATK, which process the tracking and collision physics, have been extended to enable tracking of photons using the same continuous energy approximation. We describe the four photoatomic processes implemented, which are coherent scattering, incoherent scattering, pair-production, and photoelectric absorption. The accompanying background, implementation, and verification of these processes will be presented.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Integral Criticality Estimators in MCATK

The Monte Carlo Application ToolKit (MCATK) is a component-based software toolset for delivering customized particle transport solutions using the Monte Carlo method. Currently under development in the XCP Monte Carlo group at Los Alamos National Laboratory, the toolkit has the ability to estimate the ke f f and a eigenvalues for static geometries. This paper presents a description of the estimators and variance reduction techniques available in the toolkit and includes a preview of those slated for future releases. Along with the description of the underlying algorithms is a description of the available user inputs for controlling the iterations. The paper concludes with a comparison of the MCATK results with those provided by analytic solutions. The results match within expected statistical uncertainties and demonstrate MCATK’s usefulness in estimating these important quantities.

97 MATHEMATICS AND COMPUTING↗